"The ST-X uses a new supercharger from Eaton, which packages greater volume into a compact housing. The charge-air cooler (intercooler) comes from the Japanese-market Subaru B4. The installation looks "factory" and boosts horsepower to 230 @ 5,600 rpm - a 40-percent increase over the stock engine. The supercharged engine also produces 210 lb.-ft. of peak torque - a 25 percent boost over stock - the same 4,000 rpm as the Outback engine."